HP 3600 Service Manual - Page 242

Diagnostics The following section describes the printer's diagnostics. LED diagnostics Use the following procedure to help identify the cause of high-level printer problems. These problems are indicated by abnormalities in the printer's power-on sequence. The LED that the procedure refers to is on the formatter. This is the "heartbeat" LED that blinks on and off when the formatter is operating correctly. Does the LED blink with four fast bursts at power on? If not, then perform the following checks: ● Check the firmware. ● Check the memory. ● Check the formatter. Does the LED blink at a fast, steady rate during memory testing (one blink per 8 MB)? If not, then perform the following checks: ● Check the control-panel display for an error code. ● Check the memory. ● Check the formatter. Is the LED off for about eight seconds, while the boot code is decompressing, before the display turns on? If not, then perform the following checks: ● Check the firmware. ● Check the control-panel display for correct connections and operation. ● Check the control-panel display for an error code. Does the LED blink at a steady rate of one blink per second? If not, then perform the following checks: ● Check the firmware. ● Check the formatter. ● Check the control-panel display for an error code. If the control-panel display does not illuminate, perform an engine test to check the engine. You must have media loaded in tray 2 for the engine test. Diagnostics mode Some of the diagnostics tests automatically put the printer into a special diagnostics mode. During the special diagnostics mode the printer performs actions that normally cause the printer to enter an error state. Always follow the control panel directions in the DIAGNOSTICS menu to exit the special diagnostics mode correctly and return the printer to a normal state. 230 Chapter 6 Troubleshooting ENWW